UGMENTALCASE
Aerospace
- Oct 10, 2011
- 123
Good evening all,
I've been researching GD & T and purchased some good reference books which have helped me understand a lot, however I think I'm confusing myself a bit. In examples in the books I've been reading you have a pin and a hole. Hole is tolerance 12.0 + 0.1 - 0.1, so we calculate MMC and similarly with the shaft/pin. Calculate the VC and that's it, the parts fit together.
I'm struggling to find a real life scenario, so to speak. I've attached an image the blue outline is a profile, the grey inner track is a checking pin shape. Don't ask why it's just this shape (I have a similar situation I'm looking at) The line tolerance is stated, and there are some boxed dimensions. As far as I can see the only thing defining the line, is the profile tolerance, there are no ± dimensions anywhere etc. So if I were to want a fit of something like a g6 in this profile, could someone please help me out with how you would go about calculating it please?
I've gone over it as per basic examples (briefly outlined above) but I some how convince myself I'm doing it wrong, though I don't think I am! I've put an example of what I'm looking at on the end of the attachment. I hope this comes across ok, the example on the attachment is just a random tolerance to show how the hole and pin fit together, it's not using actual fits. I think I'm missing something somewhere but like I say I keep going round in circles!
Thanks in Advance
I've been researching GD & T and purchased some good reference books which have helped me understand a lot, however I think I'm confusing myself a bit. In examples in the books I've been reading you have a pin and a hole. Hole is tolerance 12.0 + 0.1 - 0.1, so we calculate MMC and similarly with the shaft/pin. Calculate the VC and that's it, the parts fit together.
I'm struggling to find a real life scenario, so to speak. I've attached an image the blue outline is a profile, the grey inner track is a checking pin shape. Don't ask why it's just this shape (I have a similar situation I'm looking at) The line tolerance is stated, and there are some boxed dimensions. As far as I can see the only thing defining the line, is the profile tolerance, there are no ± dimensions anywhere etc. So if I were to want a fit of something like a g6 in this profile, could someone please help me out with how you would go about calculating it please?
I've gone over it as per basic examples (briefly outlined above) but I some how convince myself I'm doing it wrong, though I don't think I am! I've put an example of what I'm looking at on the end of the attachment. I hope this comes across ok, the example on the attachment is just a random tolerance to show how the hole and pin fit together, it's not using actual fits. I think I'm missing something somewhere but like I say I keep going round in circles!
Thanks in Advance
